Usually, there is some sort of storage container for storing water. However, such storage implies difficulties in maintaining the water at a temperature which prevents bacterial growth - also when destilling, it is not possible to prevent completely the existence of unwanted organisms in the transport conduits and the container. It is possible to store the water at a temperature of below 8 to 10.degree. C., or at a temperature higher than 80.degree. C. This means however energy consumption and also environmental disturbances.
At a normal room temperature there will be a bacterial growth which might cause the formation of lipopolysacharides (pyrogenes) and such are not allowed to exist in an amount exceeding a certain limit provided the water should be used for parenteral infusion solutions. Recent reports even indicate that water used for haemodialysis should be of same standard as WFI.